1. Field of the Invention
The present invention relates to a wireless transmitting method suitable for wirelessly transmitting chronologically continuous data streams (such as digital audio data and digital video data) and asynchronous data (such as commands) between for example digital audio units or between digital video units.
2. Description of the Related Art
Audio units and video units have been digitized as with for example CD (Compact Disc) players, MD (Mini Disc) recorders/players, digital VCRs, digital cameras, and DVD (Digital Versatile Disc) players. As personal computers have become common, systems that connect such digital audio units or digital video units to personal computers have been proposed. As an interface that accomplishes a system that connects such digital audio units or such digital video units to a personal computer, the IEEE 1394 interface is becoming the preferred interface.
The IEEE 1394 interface supports both an isochronous transmission mode and an asynchronous transmission mode. The isochronous transmission mode is suitable for transmitting chronologically continuous data streams such as video data and audio data at high speed. The asynchronous transmission mode is suitable for transmitting various commands and files. Since the IEEE 1394 interface supports both the isochronous transmission mode and the asynchronous transmission mode, when the IEEE 1394 interface is used, video data and audio data can be transmitted between digital audio units and between digital video units, respectively. With a personal computer connected to such digital units through the IEEE 1394 interface, the user can easily control and edit video data and audio data.
The IEEE 1394 interface is a wired interface. To structure such a system with a wired interface, cable connections are required. In addition, such cable connections tend to become complicated. Moreover, with a wired interface, it is difficult to connect units that are disposed in different rooms.
Thus, it is desired to accomplish a wireless interface that wirelessly connects digital audio units or digital video units and connects these units and a personal computer. When digital audio units or digital video units are wirelessly connected or when these units and a personal computer are wirelessly connected, as with the above-described the IEEE 1394 interface, it is desired to support both the isochronous transmission mode that allows a data stream such as video data or audio data to be transmitted at high speed and the asynchronous transmission mode that allows asynchronous data such as commands and files to be transmitted in the same manner as the IEEE 1394 interface.
However, a transmission path available with a wireless LAN is restricted. Thus, it is difficult to effectively transmit two different types of data transmission such as a data stream at high speed and asynchronous data on a wireless transmission path.
Therefore, an object of the present invention is to provide a wireless transmitting method that allows two different types of data transmission such as data streams and asynchronous data to be effectively transmitted so as to effectively transmit data between digital audio units, between digital video units, or between these units and a personal computer.
To solve the above-described problem, the present invention is a wireless transmitting method, comprising the steps of forming a frame having a predetermined time period, placing a stream transmission period and an asynchronous transmission period in the frame, the stream transmission period having a predetermined number of time slots for transmitting data, allocating isochronous data to the time slots, transmitting the isochronous data in the stream transmission period, and transmitting asynchronous data in the asynchronous transmission period.
In addition, the present invention is a wireless transmitting method, comprising the steps of forming a frame having a predetermined time period, placing a stream transmission period and an asynchronous transmission period in the frame, the stream transmission period having a predetermined number of time slots for transmitting data, allocating isochronous data to the time slots, transmitting the isochronous data in the stream transmission period, transmitting asynchronous data in the asynchronous transmission period, and changing the allocation of the time slots and widening the asynchronous transmission period of the frame so as to gather the asynchronous transmission period when a time slot is unallocated.
Moreover, the present invention is a wireless transmitting method, comprising the steps of forming a frame having a predetermined time period, placing a stream transmission period and an asynchronous transmission period in the frame, the stream transmission period having a predetermined number of time slots for transmitting data, allocating isochronous data to the time slots, transmitting the isochronous data in the stream transmission period, transmitting asynchronous data in the asynchronous transmission period, searching a data stream having time slots that are unallocated, and placing the time slots of the searched data stream to the positions of the unallocated time slots so as to gather and widen the asynchronous transmission period.
The present invention is a wireless transmitting method, comprising the steps of forming a frame having a predetermined time period, placing a stream transmission period and an asynchronous transmission period in the frame, the stream transmission period having a predetermined number of time slots for transmitting data, allocating isochronous data to the time slots, transmitting the isochronous data in the stream transmission period, and transmitting asynchronous data in the asynchronous transmission period. Thus, two different types of data transmission of data streams and asynchronous data can be effectively performed.
The present invention is a wireless transmitting method, comprising the steps of forming a frame having a predetermined time period, placing a stream transmission period and an asynchronous transmission period in the frame, the stream transmission period having a predetermined number of time slots for transmitting data, allocating isochronous data to the time slots, transmitting the isochronous data in the stream transmission period, transmitting asynchronous data in the asynchronous transmission period, and changing the allocation of the time slots and widening the asynchronous transmission period of the frame so as to gather the asynchronous transmission period when a time slot is unallocated. Thus, two different types of data transmission of data streams and asynchronous data can be effectively performed.
The wireless transmitting method further comprising the steps of searching a data stream having time slots that are unallocated, and placing the time slots of the searched data stream to the positions of the unallocated time slots so as to gather and widen the asynchronous transmission period. Thus, two different types of data transmission of data streams and asynchronous data can be effectively performed. In addition, the continuity of time slots used for a data stream can be maintained.
The above, and other, objects, features and advantage of the present invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings.